In an electrostatic copying machine, it is required that prior to the stage of exposing the surface of a photoreceptor to light, the surface of the photoreceptor be subjected to electrostatic charging. For this purpose, a main charger is placed near the photoreceptor. This main charger has a charge wire placed adjacent a photoconductive layer of the photoreceptor and made of a fine tungsten wire. As a high voltage is applied to the charge wire, corona from the charge wire makes airborne particles ionize and the ionized particles deposit on the surface of the photoreceptor to charge the surface thereof.
The aforementioned charge wire is liable to gather dust while the copying machine is in use, and the dust on the charge wire causes blurs or lines on a copied image. Therefore, it is necessary that the charge wire must be subjected to periodic cleaning.
The charge wire of the main charger is usually cleaned by opening a front casing member, taking out the main charger incorporated in the machine, and wiping the charge wire placed in the main charger.
However, any arrangement for opening the front casing member and taking out the main charger so as to clean the charge wire of the main charger is disadvantageous in that the construction of the copying machine is made complex and the copying machine is necessarily larger in size and heavier. This results in an increase in the manufacturing cost.